involved, a useful range of births prevented per acceptor of a given method is emerging.* The least reliable data continue to be on the use of conventional contraceptives, such as condoms and foam. Evaluations of the overall effects of present programs (36, 37) are beginning to indicate what effects sizeable, effective programs can have on natality rates of LDC's in 20 years. The great unknown is what proportion of families will actually use effective contraception if it is made readily available. By 1985 family planning services should be so available in many countries that the utilization rate of these services (and the resulting natality rates) will be an accurate reflection of public attitudes on family size and spacing (38). As long as contraceptive technology requires health services for delivery and as long as health services for most people are provided by the public sector, family planning services themselves will become and continue to be an important new component of government health services. Before 1985, more governments are likely to have initiated enough new actions such as direct financial, housing, educational, and other incentives and greater educational and employment opportunities for women that it will be possible to measure their effects on desires for family size, on contraceptive use, on age of marriage and on natality. Present planners in each country attempt to utilize any of the above information that is available to them and relevant to their situations to help determine the kind and size of a family planning program for their country, as well as to estimate the probable effects, particularly on natality and health services. A few examples of such planning are described next. Some National Examples Pakistan and Turkey are two countries that have published 20-year goals in terms of specific health-service:population ratios and that already have active family planning programs. Table 8 shows the number of doctors, nurses, and hospital beds that must be added between 1965 and 1985 to achieve those goals in comparison with the numbers required to maintain present ratios, with and without a successful family planning program. Based upon population estimates and health service goals of the Governments of Pakistan and Turkey, these calculations are subject to change with future experience and new data, but they do represent real and reasonably typical situations. Similar data about India from a nongovernmental source are presented in Table 9. Other countries have established shorter term goals of similar magnitude (43-46). In addition, a series of detailed health manpower studies in Taiwan, Turkey, and Peru (28-30) not only indicate the effects of population growth but also translate the need for doctors, nurses, midwives, etc. into, costs, *See for example (34, 35). Much more unpublished data have been obtained subsequently.